MONTPELIER, Vt. — Relatives of a teenager who walked out of his foster home on the eve of Tropical Storm Irene and hasn’t been seen since hope the storm’s fifth anniversary will prompt anyone who knows what might have happened to come forward and help solve the mystery.

Marble Arvidson’s mother, Sigrid Arvidson, now of Estes Park, Colorado, plans to return to Brattleboro this weekend for the first time since she moved away after her son’s disappearance.

Within the next few weeks, Marble’s aunt plans to distribute an age-progressed photograph that would show what the then-17-year boy, about to start his senior year of high school in fall 2011, might look like now.

Most of Vermont has moved on five years after the raging floods caused by Irene, with hundreds of millions of dollars in repairs completed to public infrastructure and private property. But there’s still no word on what happened to Marble. His mother doesn’t know if he’s dead or alive.

“The best I can do as a mom is to love him in whatever form he is in right now,” Sigrid Arvidson said Friday from her sister’s house in Belchertown, Massachusetts. “My desire is still to locate his physical body.”

The police and Marble’s relatives all hope the anniversary might jog someone’s memory.